1 //===-- ABISysV_x86_64.h ----------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_X86_64_H
10 #define LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_X86_64_H
11 
12 #include "Plugins/ABI/X86/ABIX86_64.h"
13 
14 class ABISysV_x86_64 : public ABIX86_64 {
15 public:
16   ~ABISysV_x86_64() override = default;
17 
18   size_t GetRedZoneSize() const override;
19 
20   bool PrepareTrivialCall(lldb_private::Thread &thread, lldb::addr_t sp,
21                           lldb::addr_t functionAddress,
22                           lldb::addr_t returnAddress,
23                           llvm::ArrayRef<lldb::addr_t> args) const override;
24 
25   bool GetArgumentValues(lldb_private::Thread &thread,
26                          lldb_private::ValueList &values) const override;
27 
28   lldb_private::Status
29   SetReturnValueObject(lldb::StackFrameSP &frame_sp,
30                        lldb::ValueObjectSP &new_value) override;
31 
32   lldb::ValueObjectSP
33   GetReturnValueObjectImpl(lldb_private::Thread &thread,
34                            lldb_private::CompilerType &type) const override;
35 
36   bool
37   CreateFunctionEntryUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
38 
39   bool CreateDefaultUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override;
40 
41   bool RegisterIsVolatile(const lldb_private::RegisterInfo *reg_info) override;
42 
43   // The SysV x86_64 ABI requires that stack frames be 16 byte aligned.
44   // When there is a trap handler on the stack, e.g. _sigtramp in userland
45   // code, we've seen that the stack pointer is often not aligned properly
46   // before the handler is invoked.  This means that lldb will stop the unwind
47   // early -- before the function which caused the trap.
48   //
49   // To work around this, we relax that alignment to be just word-size
50   // (8-bytes).
51   // Allowing the trap handlers for user space would be easy (_sigtramp) but
52   // in other environments there can be a large number of different functions
53   // involved in async traps.
54   bool CallFrameAddressIsValid(lldb::addr_t cfa) override {
55     // Make sure the stack call frame addresses are 8 byte aligned
56     if (cfa & (8ull - 1ull))
57       return false; // Not 8 byte aligned
58     if (cfa == 0)
59       return false; // Zero is not a valid stack address
60     return true;
61   }
62 
63   bool CodeAddressIsValid(lldb::addr_t pc) override {
64     // We have a 64 bit address space, so anything is valid as opcodes
65     // aren't fixed width...
66     return true;
67   }
68 
69   bool GetPointerReturnRegister(const char *&name) override;
70 
71   // Static Functions
72 
73   static void Initialize();
74 
75   static void Terminate();
76 
77   static lldb::ABISP CreateInstance(lldb::ProcessSP process_sp, const lldb_private::ArchSpec &arch);
78 
79   static llvm::StringRef GetPluginNameStatic() { return "sysv-x86_64"; }
80 
81   // PluginInterface protocol
82   llvm::StringRef GetPluginName() override { return GetPluginNameStatic(); }
83 
84 protected:
85   void CreateRegisterMapIfNeeded();
86 
87   lldb::ValueObjectSP
88   GetReturnValueObjectSimple(lldb_private::Thread &thread,
89                              lldb_private::CompilerType &ast_type) const;
90 
91   bool RegisterIsCalleeSaved(const lldb_private::RegisterInfo *reg_info);
92   uint32_t GetGenericNum(llvm::StringRef reg) override;
93 
94 private:
95   using ABIX86_64::ABIX86_64; // Call CreateInstance instead.
96 };
97 
98 #endif // LLDB_SOURCE_PLUGINS_ABI_X86_ABISYSV_X86_64_H
99